Wire-stretcher.



PATENTED MAR. 14, 1905.

W. H. SPILLER. WIRE STRETGHER.

APPLICATION FILED OUT. 10, 1904.

2 SHEETS-SHEET 1.

I PATENTED MAR. 14. 1905.

W. H. SPILLER. WIRE STRETOHER.

APPLIOATION FILED 001'. 10, 1904.

2 SHEETS-SHEET 2.

Patented March 14, 1905.

UNITED STATES PATENT OFFICE.

WILLIAM H. SPILLER, OF AURORA, ILLINOIS, ASSIGNOR TO WILOOX MANUFACTURING COMPANY, OF AURORA, ILLINOIS, A CORPO- RATION OF ILLINOIS.

WlRE-STRETCHER.

SPECIFICATION forming part of Letters Patent No. 784,813, dated March 14, 1905.

Application filed October 10,1904. $erial No. 227,884.

To (ti/Z whom, it 77'I/(LZ/ concern:

Be it known that I, IVILLIAM H. SPILLER, a citizen of theUnited States,residing atAurora, in the county of Kane and State of Illinois, have invented certain new and useful Improvements in \Vire-Stretchers, of which the following is a specification, reference being had to the accompanying drawings.

My invention, in a generic sense, has to do with gearing, but in the special embodiment thereof illustrated in the accompanying drawings and hereinafter described it has more particularly to do with wire-stretchers and analogous .devices such, for example, as jacks.

The principal object of my invention is to provide an improved arrangement of gearing which shall be self-locking in the sense that the driven gear is positively locked against initial movement 0., movement resulting from power initially applied thereto as distinguished from power communicated to said driven gear from the driving gear or pinionsuch lock being ineffective, however, to prevent driving of the driven gear by power applied initially to the driving-gear. The utility of such construction applied to a wirestretcher, for example, is obvious, since by connecting the wire to be stretched to the driven gear by a chain or other suitable device however great the tension upon said driven gear may be by reason of the stretching of the wire it is locked at all times against reverse rotation without the interposition of pawl-and-ratchet mechanism or other extraneous locking devices, and no care on the part of the operator is necessary to insure the proper locking of the gears. Heretofore attempts have been made to secure the advantages of a positive self-locking device by utilizing the friction between the parts of the ap paratus; but it is evident that where the resistance to reverse rotation of the driven gear or wheel depends upon friction only, there being no positive lock, it is only necessary to increase the tension sufiiciently to overcome the friction, when the parts will give.

My invention is distinguished from the latter class of devices in that friction has absolutely nothing to do with the lock, the lock in my improved construction being positive, although self-operating.

In the accompanying drawings I have illus trated my invention as applied to a wirestretcher; but I wish it to be understood that I have done so only in order that I might illustrate an embodiment thereof in concrete form. My invention is not restricted in its application to wire-stretchers, but is applicable to many forms of mechanical devices. The claims hereinafter made are therefore to be construed accordingly.

In the accompanying drawings, Figure 1 is a side view illustrating my invention as applied to a wire-stretcher, one side of the frame being removed and certain parts being shown in section. Fig. 2 is a plan view of the parts shown in Fig. 1. Figs. 3 and at are views illustrating different positions of the driving and driven wheels, and Fig. 5 is a diagram illustrating the manner in which the shape of the recesses between the teeth of the driven wheel is determined.

Referring to the drawings, 6 '7 indicate the side pieces of the frameof a wire-stretcher, said side pieces being connected near their ends by bolts 8 9, carrying sleeves 1U 11, respectively.

12 indicates the driven wheel or gear, which is mounted upon a shaft 13, the ends of which are pivoted in suitable bearings in the side bars 6 7. (Shown in dotted lines in Fig. 2.) The driven gear 12 is mounted near one of the side bars, as 7, and between said gear and the other side bar is a chain-gear l i, mounted on or formed with the shaft 13, so as to rotate therewith. By this construction when the driven wheel 12 is rotated it rotates the chain-gear I L.

15 indicates a chain adapted to run over the gear 14 and to be connected to a post, tree, or other lixed object in the usual way.

16 indicates the driving wheel or pinion, which is mounted upon and preferably formed integral with a shaft 17, also fitted in suitable bearings in the side bars 6 7. One end of the shaft 17 projects beyond the side bar 6 and carries a lever 18, by which saidshalt may be rotated.

As best shown in Figs. 1, 3, and at, the driven wheel 12 is provided in its periphery with a number of teeth 19, spaced equally distant apart. The periphery of the wheel 12 between said teeth is cut out somewhat in semicylindrical form, as shown at it in the drawings. Said recesses or cut-away portions are not truly semicylindrieal, but are formed in the manner shown in Fig. 5, the deepest part of said recesses t'. 0., from I) to U being the arc of a circle struck from the point 72*, while the portion from 0 to c is the arcof a circle struck from the point 0', and that part from I) to c is the arc of a circle struck from the point 0 From 0 to d is a tangent to the are c b at the point 0, while from a to (Z is a tangent to the are c I) at the point e.

20 indicates the teeth of the driving wheel or pinion 16. The shape oi the d riving-pinion is best shown in Figs. 3 and 4, from an inspection of which it will be seen that the teeth 20 are set equally distant apart and are rounded at their outer ends to [it closely in the recesses a of the driven wheel 12. Between successive teeth the pinion 16 is cut away or provided with recesses which receive the teeth 19 of the driven wheel 12. It is important to note that said recesses c are enough wider than the width of the teeth 19 at their outer ends to permit a certain amount of movement of the driven wheel independently of the driving-pinion when said wheel and pinion assume certain relations to each other. For example, when the parts are in the position shown in Fig. 3 it will be noted that the side edges of the middle tooth 19 are not in contact with either of the adjacent teeth 20 of the drivingpinion, while the lower tooth 19 is in contact with the outer end portion of the lower tooth 20; also, that if the driven wheel 12 were to be moved to carry the upper tooth 19 into contact with the outer portion of the upper tooth 20, as indicated by dotted lines in Fig. 3, the middle tooth 19 would still be out of contact with the lower teeth 20, or at least would not engage said tooth suiticiently to move the pinion 16. It will be evident, therefore, that when the parts occupy the position shown in Fig. 3 the driven wheel 12 is locked against initial movement-to any appreciable extent unless it be capable of rotating the pinion 16 by reason of the engagement of either the upper or lower tooth 19 with the outer end portion of the upper or lower tooth 20; but, as shown in Fig. 3, inasmuch as the upper and lower teeth 19 engage the upper and lower teeth 20 only at the outer end portions thereof the line of direction of any force applied initially to the driven wheel 12 as transmitted to the pinion 16 is inward, either through the axis thereof or substantially so, and consequently has no appreciable rotative eflect.

The upper and lower teeth therefore act as positive stops or locking devices, which intercept the upper or lower teeth, as the case may be, of the driven wheel 12 and positively prevent initial rotation thereof.

The recesses c in the driving-pinion are made comparatively deep, so that the axis of the driving-pinion 16 is brought closer to the periphery of the driven wheel, thereby bringing the line of direction of the force transmitted to the driving-pinion through the teeth 19 nearer the axis of said pinion, and consequently increasing the margin of stability of the lock. The increased length of the teeth 20 thus secured also contributes to the same end.

hen power is applied initially to the driving-pinion, it is transmitted through the teeth 20 to the teeth 19, so that the driven wheel 12 is continuously rotated, and said wheel may be rotated in either direction. The engagement between the teeth 20 and the teeth 19 is at lirst a rolling one. later becoming a sliding engagement.

For ordinary purposes the best results are secured by providing the driving-pinion with three teeth; but the number used may be varied, it being essential only that the drivingpinion and driven gear or wheel be so related as to bring the operating-teeth of the driven wheel into engagement with the outer end portions of the teeth 01 the driving wheel or pinion in such manner as to lock the drivingwheel against initial rotation.

It will be noted that when the parts are in locking position, as shown in Fig. 3, two of the teeth of the driving-pinion are in position to be engaged by two teeth of the driven wheel lying at opposite sides of a line intersecting the axes of said wheel and pinion, so that it' power be applied initially to the driven wheel to rotate it in either direction its teeth will be intercepted and locked by the engagement of certain of its teeth with the outer end portions of the teeth of the driving-pinion.

The term driving wheel or pinion in the foregoing description invariably refers to the pinion 16, while the term driven gear or wheel invariably refers to the gear 12, since under the only conditions in which the rotation of said wheels is possible the power must be applied initially to the pinion 16.

That which I claim as my invention, and de sire to secure by Letters Patent, is

1. A self-locking gear, comprising a driving-pinion,and a toothed wheel meshing therewith and driven thereby, said wheel being arranged. to bear inwardly upon certain teeth of said pinion when power is initially applied to said wheel to rotate it, substantially as described.

2. A self-locking gear, comprising a drivingpinion, and a toothed wheel meshing therewith and driven thereby, the teeth of said wheel being arranged to bear inwardly upon the outer end portions of the teeth of said pinion when power .is initially applied to said wheel to rotate it, substantially as described.

3. A self-locking gear, comprising a driving-pinion,and atoothed wheel meshing therewith and driven thereby, said wheel being arranged to bear inwardly upon certain teeth of said pinion when power is initially applied to said wheel to rotate it in either direction, substantiall y as described.

4. A self-locking gear, comprising a driving-pinion, and a toothed wheel meshing therewith and driven thereby, the teeth of said wheel being arranged to bear inwardly upon the outer end portions of the teeth of said pinion when power is initially applied to said wheel to rotate it in either direction, substantially as described.

5. A self-locking gear, comprising a drivingpinion, and a toothed wheel meshing therewith and driven thereby, the teeth of said pinion being arranged to intercept the teeth of said wheel and positively lock said wheel against initial reverse rotation, substantially as described.

6. A self-locking gear, comprising a driving-pinion, and a toothed wheel meshing therewith and driven thereby, the teeth of said pinion being arranged to intercept the teeth of said wheel and positively lock said wheel against initial rotation, substantially as described.

7. A self-locking gear, comprising a drivingpinion, and a toothed wheel meshing therewith and driven thereby, certain teeth of said wheel being arranged to bear inwardly upon the end portions of certain teeth of said pinion at opposite sides of a line intersecting the pivots of said wheel and pinion when power is initially applied to said wheel to rotate it in either direction, substantially as described.

8. A self-locking gear, comprising a driving-pinion, and a toothed wheel meshing there- .with and driven thereby, the teeth of said wheel being arranged to bear upon the outer end portions of the teeth of said pinion substantially toward the axis of said pinion when power is applied initially to said wheel to rotate the same, substantially as described.

9. A self-locking gear, comprising a driving-pinion, and a toothed wheel meshing therewith and driven thereby, alternate teeth of said wheel being arranged to engage the outer end portions of adjacent teeth of said pinion when power is initially applied to said wheel to rotate the same, substantially as described.

10. A self-locking gear, comprising a driving-pinion, and a toothed wheel meshing therewith and driven thereby, alternate teeth of said wheel being arranged to engage the outer end port-ions of adjacent teeth of said pinion when power is initially applied to said wheel to rotate the same, said pinion having recesses between adjacent teeth adapted to receive the intermediate teeth of said wheel and permit slight movement of said wheel independently of said pinion, substantially as described.

11. A wire-stretcher, comprisingaframe, a driving-pinion, and a driven wheel meshing with said pinion and driven thereby, said wheel and pinion being arranged to interlock against rotation when power is applied initiall y to said wheel, substantially as described.

WILLIAM H. SPILLER. 1n presence of A. M. Soo'r'r, L. R. SIMPSON. 

